Chemosphere ( IF 5.778 ) Pub Date : 2021-02-22 , DOI: 10.1016/j.chemosphere.2021.130038 Adarsh Kumar; Tripti; Maria Maleva; L. Benedict Bruno; Mani Rajkumar
Copper (Cu) is an essential element, however it’s excess into the environment causes detrimental effect on plant and risks for public health. Four Cu and drought tolerant 1-aminocyclopropane-1-carboxylate (ACC) deaminase producing rhizobacteria were isolated from the roots of Trifolium repens L. growing on Cu smelter contaminated soils, characterized and identified based on 16S rRNA gene sequencing. A consortium of high ACC deaminase (53.74 μM α-keto mg-1 protein h-1) producing bacteria Pseudomonas sp. strain TP15a + siderophore producing Bacillus aerophilus strain TP15c significantly (p < 0.05) produced better results for multiple-metal tolerance including Cu (1750 mg Kg-1), antibiotic resistance (ampicillin, kanamycin, chloramphenicol, penicillin, tetracycline, and streptomycin) and plant growth promoting attributes (phosphate solubilization: 315 mg L-1, indole-3-acetic acid (IAA) production: 8 mg L-1, ammonia and hydrogen cyanide production) as compared to individual isolates. Pot scale experiment (enriched with 100 mg Cu Kg-1) showed inoculation of Helianthus annuus seeds with consortium of TR15a+TR15c had significantly (p <0.05) improved seed germination by 32%, total dry biomass by 64%, root Cu by 47% and shoot Cu by 75% as compared to uninoculated control whereas 0.2˗7 fold higher results were observed for above stated parameters as compared to four individual isolates studied. The result suggests consortium of ACC deaminase producing Pseudomonas sp. TR15a and siderophore producing B. aerophilus TR15c could play a vital role in enhanced Cu uptake and improvement of biomass and may provide a better alternative for decontamination of Cu contaminated natural ecosystem than individual isolates.
铜（Cu）是必不可少的元素，但是铜过量进入环境会对植物造成不利影响，并危害公共健康。从生长在铜冶炼厂污染土壤上的白三叶的根中分离出四种产生铜和耐旱的1-氨基环丙烷-1-羧酸（ACC）脱氨酶的根瘤菌，并基于16S rRNA基因测序进行鉴定和鉴定。产生细菌假单胞菌的高ACC脱氨酶（53.74μMα-酮mg -1蛋白h -1）的财团。菌株TP15a +产生铁载体的嗜铁芽孢杆菌菌株TP15c菌株（p <0.05）对于包括Cu（1750 mg Kg -1）的多金属耐受性产生了更好的结果），抗生素抗性（氨苄青霉素，卡那霉素，氯霉素，青霉素，四环素和链霉素）和植物生长促进特性（磷酸盐增溶：315 mg L -1，吲哚-3-乙酸（IAA）产生：8 mg L -1，氨和氰化氢的产生）。盆栽实验（富含100 mg Cu Kg -1）显示了向日葵的接种与未接种的对照相比，由TR15a + TR15c组成的种子具有显着（p <0.05）的种子发芽提高32％，总干生物量提高64％，根铜提高47％，芽铜提高75％的效果，而未接种的对照提高了0.2˗7倍与研究的四个分离株相比，上述参数的结果得到了观察。结果表明产生ACC脱氨酶的假单胞菌sp。TR15a和产生铁载体的嗜氧芽孢杆菌TR15c在提高铜的吸收和生物量的改善中起着至关重要的作用，并且可能比单独的分离物为铜污染的自然生态系统提供了更好的替代品。